WO 01/74285 discloses a telescopic rail and carriage assembly comprising an inner rail section and an outer rail section. The inner rail section is partially received within the outer rail section so as to be telescopically displaceable in and out of the outer rail section. The outer rail section has a longitudinally extending first opening through which a trolley connector projection may extend. The first opening of the outer rail section is defined by opposed inwardly extending slot projections extending into the interior side of the outer rail section. Each of the slot projections terminates in a respective first interior support surface. The inner rail section has a longitudinally extending second opening through which the trolley connector projection may extend. The inner rail section has interior surface portions bordering the second opening on opposite sides thereof defining respective second interior support surfaces. The slot projections are configured to register within the second opening such that the first and second interior support surfaces are in an essentially common plane and define a travel support surface for the trolley component. This construction allows the trolley to travel on the support surfaces provided by the outer rail section or the inner rail section or both. The rail construction is though not particularly stable, and therefore, less suitable for carrying heavy loads.
WO 01/74285 also discloses a support structure including the telescopic rail. The rail is supported by upstanding pole components that are tensioned between the floor and the ceiling of the room where the support structure is to be used.